1. Field of the Invention
The present invention relates to an MPEG recording and playback device, and more specifically to collection, recording and playback of data relating to MPEG data by the MPEG recording and playback device.
2. Description of the Background Art
FIG. 6 is a block diagram of a conventional MPEG recording and playback device, illustrating a conceptual view of paths of recording and playback of D-VHS analog signals and digital data by the conventional MPEG recording and playback device having a digital broadcast receiving function and an IEEE 1394 interface.
This MPEG recording and playback device, as shown in FIG. 6, comprises an antenna 1, a digital receiver 2, an MPEG decoder 3, a D-VHS signal processor 4, a selection switch 5, a recording and playback amplifier 6, a rotating head 7, a magnetic tape 8, an IEEE 1394 interface (I/F) 9, a three-dimensional (3D) Y/C separation unit 10, an MPEG encoder 11, and a changer 12.
The antenna 1 receives digital broadcasts. The digital receiver 2 is tuned to a broadcast wave received with the antenna 1 for digital demodulation and extracts MPEG data. The MPEG decoder 3 decodes MPEG data extracted by the digital receiver 2 and outputs analog image and audio signals.
The D-VHS signal processor 4, during recording of MPEG data, selectively receives any one of MPEG data extracted by the digital receiver 2, MPEG data obtained by encoding analog input as described later and MPEG data fed via the IEEE 1394 I/F 9, arranges the received MPEG data in a data structure defined by the D-VHS standard and, after adding an error correction code, converts and outputs it as a recording signal. During playback, the D-VHS signal processor 4 receives a digital playback signal from the selection switch 5 as described later and, after performing error correction processing, extracts and outputs an MPEG stream from the digital playback signal.
The selection switch 5, during recording, selects and outputs either digital recording signal output from the D-VHS signal processor 4 or analog recording signal output from analog input as described later. During playback, the selection switch 5 receives a playback signal from the recording and playback amplifier 6 as described later and outputs it to the D-VHS signal processor 4 or the 3D Y/C separation unit 10 depending on whether the signal is in analog or digital form.
The recording and playback amplifier 6, during recording, subjects a recording signal received from the selection switch 5 to waveform equalization and amplification, thereby to generate and output a magnetic recording signal. During playback, the recording and playback amplifier 6 performs processing such as waveform equalization and phase compensation on a signal read out by the rotating head 7 as described later for minimizing magnetic-media-specific waveform distortion and the like, thereby to output a playback signal. The rotating head 7 performs reading and writing of a recording signal from and to the magnetic tape 8. The IEEE 1394 I/F 9 exchanges an MPEG stream and a control command with external digital AV equipment in accordance with the IEEE 1394 standard.
With respect to analog input (analog image and audio signals) from outside, when the analog image signal is a composite signal, the 3D Y/C separation unit 10 outputs the image signal without any additional processing or after performing 3D Y/C separation processing to the selection switch 5 together with the analog audio signal. When the image signal is a Y/C signal, the 3D Y/C separation unit 10 outputs the image signal without any additional processing to the selection switch 5 together with the audio signal. Simultaneously with this output to the selection switch 5, the 3D Y/C separation unit 10 outputs an A/D converted audio signal and an image component signal such as a Y/C signal to the MPEG encoder 11 as described later.
The MPEG encoder 11 receives the image component signal and the A/D converted audio signal from the 3D Y/C separation unit 10 and performs MPEG encoding to generate and output MPEG data. The changer 12 selects an input/output signal from the digital receiver 2, the IEEE 1394 I/F 9, the MPEG decoder 3 and the D-VHS signal processor 4 and distributes the selected signal.
First, the act of recording MPEG data received from digital broadcasting on the magnetic tape 8 will be described with reference to FIG. 6. A broadcast wave received from digital broadcasting with the antenna 1 is subjected to processing such as channel selection, digital demodulation and error correction by the digital receiver 2 and is outputted as an MPEG stream.
The outputted MPEG stream is fed via the changer 12 to the D-VHS signal processor 4 and the MPEG decoder 3. The MPEG decoder 3 decodes the received MPEG stream to generate and output, for example, image and audio signals, thereby providing audio and video to viewers. The D-VHS signal processor 4 rearranges the received MPEG stream in a data format compliant with the D-VHS standard and, after adding an error correction code, outputs it as a recording signal to the selection switch 5.
The recording signal outputted from the selection switch 5 is fed to the recording and playback amplifier 6, in which the signal is formed into a waveform suitable for magnetic tape recording, converted into a magnetic recording signal, and outputted to the rotating head 7. This magnetic recording signal is recorded on the magnetic tape 8 by the rotating head 7.
Next, the act of recording MPEG data generated by encoding analog input signals from outside on the magnetic tape 8 will be described with reference to FIG. 6. Analog image and audio signals received from outside are fed to the 3D Y/C separation unit 10, in which the image signal is subjected to Y/C separation processing and fed to the MPEG encoder 11 together with the audio signal.
The MPEG encoder 11 performs MPEG encoding of the received image Y/C and audio signals, edits both the signals and a necessary data table, and transmits a result as an MPEG transport stream (hereinafter referred to as an “MPEG-TS”) to the D-VHS signal processor 4.
The D-VHS signal processor 4 rearranges the received MPEG stream in a data format compliant with the D-VHS standard and, after adding an error correction code, outputs it as a recording signal to the selection switch 5.
The recording signal outputted from the selection switch 5 is fed to the recording and playback amplifier 6, in which the signal is formed into a waveform suitable for recording on the magnetic tape 8, converted into a magnetic recording signal, and outputted to the rotating head 7. This magnetic recording signal is recorded on the magnetic tape 8 by the rotating head 7.
Herein analog recording and playback in S-VHS or VHS modes using similar input signals, which are irrelevant to the present invention, will not be described.
Next, the act of recording MPEG data received from the IEEE 1394 I/F 9 on the magnetic tape 8 will be described with reference to FIG. 6. MPEG data received from the IEEE 1394 I/F 9 is transmitted via the changer 12 to the MPEG decoder 3 and the D-VHS signal processor 4.
The MPEG decoder 3 decodes the received MPEG stream to generate and output image and audio signals, thereby providing audio and video to viewers. The D-VHS signal processor 4 rearranges the received MPEG stream in a data format compliant with the D-VHS standard and, after adding an error correction code, outputs it as a recording signal to the selection switch 5.
The recording signal outputted from the selection switch 5 is fed to the recording and playback amplifier 6, in which the signal is formed into a waveform suitable for magnetic tape recording, converted into a magnetic recording signal, and outputted to the rotating head 7. This magnetic recording signal is recorded on the magnetic tape 8 by the rotating head 7.
Finally, the act of playing back and MPEG decoding MPEG data recorded on the magnetic tape 8 will be described with reference to FIG. 6. MPEG data recorded on the magnetic tape 8 is converted from a magnetic pattern into an electric signal by the rotating head 7 and fed to the recording and playback amplifier 6.
The recording and playback amplifier 6 performs processing such as waveform equalization and phase compensation on the received electric signal for minimizing magnetic-medium-specific waveform distortion and the like, and transmits the processed electric signal as a playback signal via the selection switch 5 to the D-VHS signal processor 4.
The D-VHS signal processor 4 creates a data block compliant with the D-VHS standard for the playback signal received from the selection switch 5 and, after performing error correction processing, decomposes data into MPEG-TS packets to construct MPEG data. The MPEG data is then fed via the changer 12 to the MPEG decoder 3.
The MPEG decoder 3 performs image and audio decoding through processing necessary for MPEG decoding on the received MPEG data such as filtering for extracting image and audio data and retrieval of time-stamp information for use in defining the timing of decoding, and then outputs resultant analog image and audio signals to the outside.
The MPEG decoder 3 also extracts pertinent information on program, called SI (Service Information) data, from the received MPEG data and, by interpreting the information, provides pertinent information on a program being played back such as the title of the program and the duration of the broadcast time of the program.
As above described, in the conventional MPEG recording and playback device, only the MPEG decoder 3 can handle pertinent information on program. Thus, MPEG recording and playback devices which are not equipped with an MPEG decoder cannot handle pertinent information on program and accordingly cannot provide pertinent information on a program being played back to viewers.
Further, when an MPEG recording and playback device which is not equipped with an MPEG decoder is connected to a digital TV or set top box (STB) equipped with an MPEG decoder, the digital TV or STB cannot know whether the MPEG recording and playback device connected thereto has storage for pertinent information on program and thus cannot transmit proper pertinent information on program to the MPEG recording and playback device. Further, the MPEG decoder may not have the function of displaying pertinent information on a program being played back.